我需要在多选表单中选择多个值：选择标签。我的jsp代码是
<form:form id="myForm"
action="service.do" modelAttribute="services"
method="POST">
....
....
<form:select path="channelsInvolved" items="${allChannels}" itemValue="channelid" itemLabel="channelname">
我的控制器是...
List<Channels> channels = dao.getAllChannels();
model.addAttribute("allChannels", channels);
ServiceRegistration serRegistration = dao.getById(2);
model.put("services", serRegistration);
实际上，我有 3 个表 -> ServiceRegistration、Channels（包含 META 数据）和 ServiceChannel。ServiceChannel 包含与 serviceregistration 和通道表的外键引用。因此，一个 serviceid 可能在 servicechannel 表中映射了多个 channelid。
我的 ServiceRegistration.java 实体类的 channelsInvolved 字段为...
@OneToMany(cascade=CascadeType.ALL,fetch = FetchType.EAGER)
@JoinTable(name = "ServiceChannel", joinColumns = {
@JoinColumn(name="serviceid", unique = true)
},
inverseJoinColumns = {
@JoinColumn(name="channelid")
}
)
private List<Channels> channelsInvolved;
public List<Channels> getChannelsInvolved() {
return channelsInvolved;
}
public void setChannelsInvolved(List<Channels> channelsInvolved) {
this.channelsInvolved = channelsInvolved;
}
频道实体类... Channels.java
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column private int channelid;
@Column private String channelname;
ServiceChannel.java 实体类...
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column private int servicechannelid;
@ManyToOne
@JoinColumn(name = "serviceid")
private ServiceRegistration serviceRegistration;
@ManyToOne
@JoinColumn(name = "channelid")
private Channels channels;
比如说，我有一个服务 id >> 2 映射到 channelid >> 1 和 2。我可以在“channelsInvolved”中看到 2 条记录。但是当我将 serRegistration 设置为 jsp 的模型属性时，在 select 标记中没有选择任何内容。
帮助表示赞赏，谢谢。